Transcript Internet and LAN Technology

Internet and LAN
Technology
Chapter Contents
•
•
•
•
Section A: Network Building Blocks
Section B: Local Area Networks
Section C: Internet Technology
Section D: Internet Access
2
Section A: Network Building
Blocks
• Network Advantages and Challenges
• Network Classifications
• Geographic Scope: PANs, NANs, LANs,
MANs, and WANs
• Organizational Structure: Client/Server
and Peer-to-Peer
• Physical Topology
3
Section A: Network Building
Blocks
•
•
•
•
Network Links
Analog and Digital Signals
Bandwidth
Communications Protocols
4
Network Advantages and
Challenges
• Sharing networked hardware can reduce costs
• Sharing networked hardware can provide
access to a wide range of services and
specialized peripheral devices
• Sharing networked software can reduce costs
• Sharing data on a network is easy
• Networks enable people to work together
regardless of time and place
5
Network Advantages and
Challenges
• Networks may be vulnerable to
unauthorized access from many sources
and locations
– More vulnerable than standalone computers
• Wireless networks can be tapped from a
“snooping” computer
• Networked computers are susceptible to
an increasing number of worms, Trojan
horses, and blended threats
6
Network Classifications
7
Geographical Scope: PANs, NANs,
LANs, MANs, and WANs
• Personal Area Network (PAN) – interconnection
of personal digital devices
• Neighborhood Area Network (NAN) –
connectivity spread over several buildings
• Local Area Network (LAN) – usually connects
computers in a single building
• Metropolitan Area Network (MAN) – public highspeed network with range of about 50 miles
• Wide Area Network (WAN) – consists of several
smaller networks
8
Organizational Structure:
Client/Server and Peer-to-Peer
9
Physical Topology
• Arrangement of devices in a network
• Each connection point on a network is
referred to as a node
• A bridge can connect two similar networks
• A gateway joins two dissimilar networks
– Router
10
Physical Topology
11
Physical Topology
12
Network Links
• Wired network
– Twisted-pair cable
– Coaxial cable
– Fiber-optic cable
• Wireless network
– RF signals
– Microwaves
– Infrared light
13
Analog and Digital Signals
14
Bandwidth
• The transmission capacity of a
communications channel
– High-bandwidth channel (broadband)
• Cable TV
• DSL
– Low-bandwidth channel (narrowband)
• Telephone system
15
Communications Protocols
• Rules for efficiently transmitting data from
one network node to another
– Dividing messages into
packets
– Affixing addresses to
packets
– Initiating transmission
– Regulating the flow of data
– Checking for transmission errors
– Acknowledging receipt of transmitted data
16
Communications Protocols
• A packet is a “parcel” of data that is sent
across a computer network
– Circuit-switching technology vs. packet
switching technology
• Voice over IP (VoIP)
17
Section B: Local Area Networks
•
•
•
•
•
•
LAN Standards
Ethernet
Wi-Fi
HomePNA and HomePLC Networks
Installing a LAN
Using a LAN
18
LAN Standards
• LAN Technologies are standardized by the
IEEE
– ARCnet
– Token Ring technology
– FDDI
– Ethernet
– Wi-Fi
19
Ethernet
• Simultaneously broadcasts data packets
to all network devices
– IEEE 802.3
– CSMA/CD protocol
20
Ethernet
On an Ethernet, data
travels on a “first come, first
served” basis. If two
workstations attempt to
send data at the same time,
a collision occurs.
That data must be resent.
CLICK TO START
21
Ethernet
• Varies in speed from 10 Mbps to 10 Gbps
• An Ethernet card is designed to support
the Ethernet protocols
• Ethernet hubs link workstations via cables
– Uplink port
22
Wi-Fi
• Wireless networking technologies that are
compatible with Ethernet
23
Wi-Fi
• WEP (Wired Equivalent Privacy) encrypts
data traveling over wireless networks
• Equipment required for a wireless
network
– Wi-Fi card
– Wireless access point
• Bluetooth is a short-range
wireless network technology
24
HomePNA and HomePLC
Networks
• HomePNA networks utilize existing
telephone wiring to connect network
devices
– Special NICs and cables are required
• HomePLC networks transmit data over
power lines as low-frequency radio waves
25
Installing a LAN
CLICK TO START
26
Using a LAN
In this drive mapping
example, a server’s drive
C is mapped as drive F
by a workstation.
After the mapping is complete,
the server’s hard disk appears
in the workstation’s directory as
drive F and can be used just as
though it were a drive
connected directly to the
workstation.
CLICK TO START
27
Using a LAN
• You can allow other
network users to view
and edit files in the
folders you’ve
designated as shared
28
Using a LAN
• The Network Connection tool helps you
troubleshoot connection problems
29
Section C: Internet Technology
•
•
•
•
•
•
Background
Internet Structure
ISP Infrastructure
Internet Protocols
IP Addresses
Domain Names
30
Background
• The Advanced
Research Projects
Agency designed
ARPANET
• The Internet has an
estimated 200 million
nodes and 500 million
users today
31
Internet Structure
32
Internet Structure
• Ping is used to find out whether a site is
up and running
• The Traceroute utility records a packet’s
path
33
ISP Infrastructure
34
Internet Protocols
• TCP and IP serve as the primary protocols
responsible for message transmission on
the Internet
35
IP Addresses
• IP addresses are addresses that identify
computers on the Internet
– Static IP address
– Dynamic IP address
36
Domain Names
• Easy-to-remember names for Internet
servers
– Ends with an extension that indicates its toplevel domain
• Every domain name corresponds to a
unique IP address
– Domain Name System
• ICANN coordinates technical management
of the Internet’s Domain Name System
37
Domain Names
38
Domain Names
The first step in registering
a domain name is to find out
whether the name is currently
in use or reserved for future
use. If a domain name is not
available, consider using a
different top-level domain,
such as biz instead of com.
After you’ve found an
available domain name you
like, you can continue the
registration process by filling
out a simple online form.
CLICK TO START
39
Section D: Internet Access
•
•
•
•
•
•
•
Dial-up Connections
Cable Internet Service
DSL, ISDN, and Dedicated Lines
Wireless Internet Services
LAN Internet Access
Mobile Internet Access
Internet Connection Roundup
40
Dial-up Connections
• Uses POTS to transport data between
your computer and your ISP
• A modem converts digital signals from
your computer into analog signals that can
travel over telephone lines, and vice versa
– Modulation / Demodulation
41
Dial-up Connections
• Modems are still
required, despite
digital telephone
technology
• Modem speed is
measured as baud
rate
• Many Internet
connection methods
provide faster
downstream
transmission rates
than upstream rates
42
Cable Internet Service
43
Cable Internet Service
• Cable modems convert your computer’s
signal into one that can travel over the
CATV network
• Always-on connection
• Neighborhood network
44
DSL, ISDN, and Dedicated
Lines
• DSL is a high-speed, digital, always-on
Internet access technology that runs over
standard telephone lines
– DSLAM
– Most DSL installations require service
technicians
• DSL modem
45
DSL, ISDN, and Dedicated
Lines
• ISDN connections are slower than DSL
and cable Internet service, but faster than
dial-up
– ISDN terminal adapter connects a computer
to a telephone wall jack and converts signals
to travel over ISDN connection
• T1, T3, and T4 lines are leased from the
telephone company, and offer fast, highcapacity data transmission
46
Wireless Internet Service
• Direct satellite service (DSS)
47
Wireless Internet Service
• Fixed wireless Internet service broadcasts
RF signals in order to offer Internet access
to large areas
– WiMAX
– Wireless service providers are usually local or
regional businesses
48
LAN Internet Access
• Cost-effective way to share one Internet
connection among several computers
• To establish LAN Internet access, you
need:
– An operational wired or wireless LAN
– A router or a hub with router capabilities
– A high-speed Internet connection, such as
DSL, ISDN, or cable Internet
– A modem that corresponds to your Internet
connection type
49
Mobile Internet Access
• A Wi-Fi hotspot is a wireless broadband
Internet service offered in a public location
– WISP
• WAP is a communications protocol that
provides Internet access from handheld
devices
50
Mobile Internet Access
• Handheld device services include:
– Short message service (SMS)
– Multimedia messaging (MMS)
– Music fingerprinting
– Games
– City guides
– E-mail
– News, sports, stocks, and weather
51
Mobile Internet Access
• Cellular service options
52
Internet Connection Roundup
53
CHAPTER 5 COMPLETE
Internet and LAN Technology